Optimization of Tissue Culture Regeneration System for Soapwort

In order to optimize the tissue culture and rapid propagation technology for soapwort, the tender stems, leaves and leaf axils of soapwort were used as the experimental materials. The MS medium supplemented with 6-BA (2.0 mg·L⁻¹) + 2,4-D (0.5 mg·L⁻¹) + 10% coconut milk was employed to screen the optimal explant sites and disinfection time. Further, an L₉(3⁴) orthogonal test was conducted by using MS, 1/2MS, and WPM as the basic medium. Different concentrations of 6-BA, NAA and different sterile water control time were added to screen out the optimum medium for the growth of leaf axils of explants and the best formula for inducing the green callus. At the same time, the growth of soapwort tissue-cultured seedlings under different medium and hormone ratios was also compared. The results showed that the best part of the explants for soapwort was leaf axil, the best disinfection time was 8 min, and the survival rate was the highest, which was 58.58%. The optimum medium combination for the growth of leaf axils was 1/2 MS + 6-BA (0.5 mg·L⁻¹) + NAA (0.05 mg·L⁻¹) + sterile water control for 3 days, and the callus germination rate was the best (20%), which was higher than those of other treatments. The optimum medium combination for inducing the green callus from leaf axils was WPM + 6-BA (0.1 mg·L⁻¹) + NAA (0.2 mg·L⁻¹) + sterile water control for 3 days, and the germination rate was 60%. The results of this study provided a reference for the efficient regeneration system and tissue culture technology of soapwort, and also provided the high-quality seedlings and technical guidance for the industrialized seedling of soapwort.